Process of and material for the production of carbide and reduction of ore



' Patented May 13, 1924.

UNITED STATES PATENT OFFICE.

JAMES HENRY ,REID, OF READSIBORO, VERMONT, ASSIGNOR TO INTERNATIONAL NITROGEN COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF DELAWARE.

PROCESS OF AND MATERIAL FOR THE PRODUCTION OF CARBIDE AND REDUCTION OI ORE.

No Drawing.

To all whom it may concern:

Be it known that I, JAMES HENRY Ram, a citizen of theUnited States, residing at Readsboro, in the county of Bennington and State of Vermont, have invented a certain new and useful Improvement in Processes of and Material for the Production of Carbide and Reduction of Ore, of which the following is a full, clear, and exact description. V

This invention relates to a process of and material for the production of carbide and reduction of ore. The general object of the invention is to provide a process whereby the production of the carbide and the reduction of the ore may be accomplished simultaneously and efiiciently and, 1n connection with such production and reduction, to generate a large quantity of gas of a heating value useful in the industrial arts.

Further objects and advantages of the invention will ap ear hereinafter in connection with the etailed description of the process, which will be explained in connection with the production of calcium carbide and the reduction of iron ore. For the reducing agent, I employ carbon, obtaining the same from bituminous coal. I also endploy calcium carbonate (preferably in the commercial form of limestone) as a fiuxing agent and as the source of the metal constituent of the carbide. Sufiicient coalwill be employed to provide the coke necessary for the carbide reaction andfor the reduction of the ore, and sufiicient limestone will be employed to furnish the metal constituent of the carbide and the fluxing agent for the ore. A mixture for this purpose will consist of the following ingredients in about the following proportions by weight I Per cent.

Bituminous coal 39 Limestone L 36.1

Iron ore (ferric oxide) 24.9

The limestone will be ground, preferably to a fineness of about fort mesh and the coal to a fineness of about elght mesh, while the ore as generally obtained will ordinarily Application filed January 27, 1981. Serial Nb. 440,342.

be sufiiciently fine, with the exception of the nodules, which should also be ground 01- otherwlse broken up. The limestone, coal and ore are then intimately mixed and are retorted for a length of time and at a temperature sufficient to convert the coal into coke. The temperature may vary from 1400 F. to 2600 or 2800 F., and the time required for the operation will vary inversely with the temperature.

By the retorting operation, the-coal will have been converted into coke, with the evolution, not only of the gases ordinarily secured by the distillation thereof, but of add1t1onal gases produced by the breaking up of the tarryconstituents of the coal in and through their contact with the glowing particles of limestone and ore. Because of'the fact that the retorting operation is conducted in a reducing atmosphere, at least as long as hydrocarbon vapors are present, ilahe limestone will not be converted into During the coking operation. the charge of ore, coal, and limestone, will have been converted into the following constituents, the ore having been partly reduced during such operation:

- Percent. Iron and ferrous oxide 24.9 Coke 29.0 Limestone 36.1 Gas 10.0

The composition of the solid residue from the retorts will be P k I .Per cent. Iron and ferrous oxide 27.7 Coke 32.2 Limestone 40.1

stone and coke necessary for its reduction, and each particle of limestone has immediately adjacent thereto one or more particles of coke for the carbide reaction.

The coked mass from the retort is broken to suitable size and is then charged into an electric carbide furnace, which may be of such as heating the retorts, running any type from which the molten material may be withdrawn from tlme to time. In the furnace, the material is subjected to the action of electricity in the ordinary manner, resulting in the fusing and reduction of the ore and in the production of carbide, the iron and carbide being produced from a common homo eneous charge and through the same operation of the furnace. Owing to the fact that the calclum is in the form of limestone, the carbide reaction will occur at a temperature below that at which the iron will volatilize. During the operation of the furnace, a large quantity of gas (principally carbon monoxide) will be evolved, and th1s gas may be collected, together with the gases from the retorts, and used for various purpoiis,

e ele'ctric generator which operates the furnace, or for any commercial or industrial purpose. I

Fusion in the electric furnace Wlll produce from 100 lbs. of the solid residue from the retorts the following:

Iron 12.5 73% carbide 25.2 Slag 28.3 Gas 24.0

But, as the carbide and the slag are mixed,

the molten educt from the electric furnace from such 100 lb. charge will be:

' Lbl.

Iron 1215 34% carbide 53.5

As the molten material accumulates in the furnace it may be withdrawn from time to time into a suitable pot or receptacle where the carbide, owing to its higher point of fusion, will solidify and float upon the molten iron and from which it and the slag reduction of ore; and, by a single treatment in an electric furnace, I have reduced the ore and have produced a grade of carbide that is capable of efiicient use, particularly in the production of nitrified material. F urthermore, in the practice of the process, I have been enabled to obtain from a given quantity of cokable coal a quantity of gas not only valuable foruse in the industrial arts, but greatly in excess of the quantity which has heretofore been considered as obtainable from the same.

In the process as thus particularly described, I have selected iron as the metal ingredient of the ore and calcium as the metal ingredient of the fiuxing agent, for the reason that the said ore is the one most used in the arts and because carbide of calcium is the one enerally used for the preparation of nitri ed material. However, by using silica in place of the limestone, we have a fiuxing agent which is capable of producing silicon carbide, or carborundum:

and an impure carborundum (containingslag in the proportions set forth) will be capable of extensive use in the arts. Hence my process is not to be limited to the pro duction of calcium carbide nor to the use of limestone as a fluxin a ent.

Having thus descri 0 my invention what I claim 15:

1. The process of producing gas and carbide and reducing ore which comprises heating in a retort closed to the atmos here a mixture of ore, limestone, and coka le carbonaceous material in proportions suitable to furnish the limestone andcoke necessary for the carbide reaction and for the ore reduction, collecting the combustible gases evolved during the retorting operation, reducing the solid educt in an electric furnace thereby toobtain carbide and the metal of the ore, collecting the evolved combustible gadses, and separating the metal and the car- 2. The process of producing carbide and reducing ore which comprises retorting a mixture of ore, limestone and cokable carbonaceous material in proportions suitable to furnish the limestone and coke necessary for the carbide reaction and for the ore reduction and without material reduction of such limestone, and reducing the solid educt in an electric furnace thereby to produce carbide and the metal of the ore.

3. The process of producing a metallic carbide and reducing an ore which com rises retorting a mixture of such ore with co able carbonaceous material and with a 'fluxing agent containing the metal ingredient of such carbide, collecting the evolved gases, reducing the solid educt in an electric furnace at a temperature sufiicient to secure the carbide reaction, and collecting the evolved gases.

4. The process of producing a metallic carbide and reducing an ore whlch comprises heating in a retort closed to the atmosphere a mixture of such ore with cokable carbonaceous material and with a carbonate containing the metal ingredient of such carbide, and reducing the solid educt in an electric furnace at a temperaturesufiicient to secure the carbide reaction.

5. Material for the production of carbide and reduction of ore consistin of a coked mixture of carbonaceous material with such ore and a fluxing agent containing the metal ingredient of the carbide.

6. Material for the production of carbide and reduction of ore consistin of a coked mixture of carbonaceous material with such ore and with limestone.

7. Material for the production of carbide and reduction of iron ore consisting of coked 2 mixture containing the followin ingredients in about the proportions spec1fied:

Per cent. Ore 27.7 Coke 32.2 26 Limestone 40.1

8. Material for the production of carbide and reduction of iron ore consisting of a mixture containing the following in redi- 

